1. Field of the Invention
The present invention relates to a molded motor including a stator having multiple teeth molded with resin, and an electric vehicle equipped with the molded motor.
2. Description of the Related Art
A molded motor has been widely used as a drive source for an electric vehicle, a washing machine and the like.
The molded motor includes an annular stator and a rotor disposed inside the stator. The stator has multiple teeth molded with resin. An insulator surrounds a periphery of each of the teeth, and a coil is wound around a periphery of the insulator.
Here, various efforts have been made to improve a rated output by efficiently releasing heat from a coil heated by energization (see, for example, Japanese Patent Application Publication No. 2008-178190, hereinafter Patent Document 1). Patent Document 1 discloses a method for transmitting the heat of the coil to a housing through a heatsink.
Meanwhile, there has been proposed a method for transmitting the heat of the coil to the teeth having a high thermal conductivity through the insulator around which the coil is wound (see Japanese Patent Application Publication No. 2001-128402, hereinafter Patent Document 2). This method does not need to provide the heatsink. Thus, miniaturization of the motor and cost reduction can be achieved.
However, in the molded motor, the teeth, insulators and coils are molded with resin. Thus, the method described in Patent Document 2 has its limits in improving heat release properties. In other words, an increase in heat transfer paths for releasing heat from the coils allows for more efficient heat release.